Germinal epithelial cells are the cells that line the seminiferous tubules in the testes and the surface of the ovary in females. These cells are cuboidal in shape and play a vital role in the production of gametes (sperm and eggs).

Role in Testes:
In the testes, germinal epithelial cells are responsible for the production of sperm through a process called spermatogenesis. These cells undergo mitosis to produce spermatogonia, which then undergo meiosis to produce haploid sperm cells. The germinal epithelial cells also provide support cells known as Sertoli cells, which play a role in the development and maturation of sperm cells.

Role in Ovary:
In females, the germinal epithelial cells play a role in the development of ovarian follicles, which contain immature egg cells. These cells divide and differentiate to form the granulosa cells that surround the egg cells within the follicle. The germinal epithelial cells also provide support cells known as Theca cells, which play a role in the production of estrogen.

Conclusion:
Therefore, it can be concluded that germinal epithelial cells are found in both the testes and ovaries, and they play a crucial role in the production and maturation of gametes in both males and females.